Teitl clawr = Cover title.
Grymoedd. Uned 4, Uned o waith i gefnogi addysgu, dysgu ac asesu prosesau ffisegol yng nghyfnod allweddol 2, gan ganolbwyntio ar ddeall grymoedd a'u heffeithiau. ISBN 1861123701. Published by Awdurdod Cymwysterau, Cwricwlwm ac Asesu Cymru in 2001. Publication and catalogue information, links to buy online and reader comments.